core-extra/daemon/examples/netns/howmanynodes.py
2013-08-29 14:21:13 +00:00

209 lines
7.9 KiB
Python
Executable file

#!/usr/bin/python
# Copyright (c)2010-2012 the Boeing Company.
# See the LICENSE file included in this distribution.
#
# author: Jeff Ahrenholz <jeffrey.m.ahrenholz@boeing.com>
#
'''
howmanynodes.py - This is a CORE script that creates network namespace nodes
having one virtual Ethernet interface connected to a bridge. It continues to
add nodes until an exception occurs. The number of nodes per bridge can be
specified.
'''
import optparse, sys, os, datetime, time, shutil
try:
from core import pycore
except ImportError:
# hack for Fedora autoconf that uses the following pythondir:
if "/usr/lib/python2.6/site-packages" in sys.path:
sys.path.append("/usr/local/lib/python2.6/site-packages")
if "/usr/lib64/python2.6/site-packages" in sys.path:
sys.path.append("/usr/local/lib64/python2.6/site-packages")
if "/usr/lib/python2.7/site-packages" in sys.path:
sys.path.append("/usr/local/lib/python2.7/site-packages")
if "/usr/lib64/python2.7/site-packages" in sys.path:
sys.path.append("/usr/local/lib64/python2.7/site-packages")
from core import pycore
from core.misc import ipaddr
from core.constants import *
GBD = 1024.0 * 1024.0
def linuxversion():
''' Return a string having the Linux kernel version.
'''
f = open('/proc/version', 'r')
v = f.readline().split()
version_str = ' '.join(v[:3])
f.close()
return version_str
MEMKEYS = ('total', 'free', 'buff', 'cached', 'stotal', 'sfree')
def memfree():
''' Returns kilobytes memory [total, free, buff, cached, stotal, sfree].
useful stats are:
free memory = free + buff + cached
swap used = stotal - sfree
'''
f = open('/proc/meminfo', 'r')
lines = f.readlines()
f.close()
kbs = {}
for k in MEMKEYS:
kbs[k] = 0
for l in lines:
if l[:9] == "MemTotal:":
kbs['total'] = int(l.split()[1])
elif l[:8] == "MemFree:":
kbs['free'] = int(l.split()[1])
elif l[:8] == "Buffers:":
kbs['buff'] = int(l.split()[1])
elif l[:8] == "Cached:":
kbs['cache'] = int(l.split()[1])
elif l[:10] == "SwapTotal:":
kbs['stotal'] = int(l.split()[1])
elif l[:9] == "SwapFree:":
kbs['sfree'] = int(l.split()[1])
break
return kbs
# node list (count from 1)
nodelist = [None]
switchlist = []
def main():
usagestr = "usage: %prog [-h] [options] [args]"
parser = optparse.OptionParser(usage = usagestr)
parser.set_defaults(waittime = 0.2, numnodes = 0, bridges = 0, retries = 0,
logfile = None, services = None)
parser.add_option("-w", "--waittime", dest = "waittime", type = float,
help = "number of seconds to wait between node creation" \
" (default = %s)" % parser.defaults["waittime"])
parser.add_option("-n", "--numnodes", dest = "numnodes", type = int,
help = "number of nodes (default = unlimited)")
parser.add_option("-b", "--bridges", dest = "bridges", type = int,
help = "number of nodes per bridge; 0 = one bridge " \
"(def. = %s)" % parser.defaults["bridges"])
parser.add_option("-r", "--retry", dest = "retries", type = int,
help = "number of retries on error (default = %s)" % \
parser.defaults["retries"])
parser.add_option("-l", "--log", dest = "logfile", type = str,
help = "log memory usage to this file (default = %s)" % \
parser.defaults["logfile"])
parser.add_option("-s", "--services", dest = "services", type = str,
help = "pipe-delimited list of services added to each " \
"node (default = %s)\n(Example: 'zebra|OSPFv2|OSPFv3|" \
"vtysh|IPForward')" % parser.defaults["services"])
def usage(msg = None, err = 0):
sys.stdout.write("\n")
if msg:
sys.stdout.write(msg + "\n\n")
parser.print_help()
sys.exit(err)
(options, args) = parser.parse_args()
for a in args:
sys.stderr.write("ignoring command line argument: '%s'\n" % a)
start = datetime.datetime.now()
prefix = ipaddr.IPv4Prefix("10.83.0.0/16")
print "Testing how many network namespace nodes this machine can create."
print " - %s" % linuxversion()
mem = memfree()
print " - %.02f GB total memory (%.02f GB swap)" % \
(mem['total']/GBD, mem['stotal']/GBD)
print " - using IPv4 network prefix %s" % prefix
print " - using wait time of %s" % options.waittime
print " - using %d nodes per bridge" % options.bridges
print " - will retry %d times on failure" % options.retries
print " - adding these services to each node: %s" % options.services
print " "
lfp = None
if options.logfile is not None:
# initialize a csv log file header
lfp = open(options.logfile, "a")
lfp.write("# log from howmanynodes.py %s\n" % time.ctime())
lfp.write("# options = %s\n#\n" % options)
lfp.write("# numnodes,%s\n" % ','.join(MEMKEYS))
lfp.flush()
session = pycore.Session(persistent=True)
switch = session.addobj(cls = pycore.nodes.SwitchNode)
switchlist.append(switch)
print "Added bridge %s (%d)." % (switch.brname, len(switchlist))
i = 0
retry_count = options.retries
while True:
i += 1
# optionally add a bridge (options.bridges nodes per bridge)
try:
if options.bridges > 0 and switch.numnetif() >= options.bridges:
switch = session.addobj(cls = pycore.nodes.SwitchNode)
switchlist.append(switch)
print "\nAdded bridge %s (%d) for node %d." % \
(switch.brname, len(switchlist), i)
except Exception, e:
print "At %d bridges (%d nodes) caught exception:\n%s\n" % \
(len(switchlist), i-1, e)
break
# create a node
try:
n = session.addobj(cls = pycore.nodes.LxcNode, name = "n%d" % i)
n.newnetif(switch, ["%s/%s" % (prefix.addr(i), prefix.prefixlen)])
n.cmd([SYSCTL_BIN, "net.ipv4.icmp_echo_ignore_broadcasts=0"])
if options.services is not None:
session.services.addservicestonode(n, "", options.services,
verbose=False)
n.boot()
nodelist.append(n)
if i % 25 == 0:
print "\n%s nodes created " % i,
mem = memfree()
free = mem['free'] + mem['buff'] + mem['cached']
swap = mem['stotal'] - mem['sfree']
print "(%.02f/%.02f GB free/swap)" % (free/GBD , swap/GBD),
if lfp:
lfp.write("%d," % i)
lfp.write("%s\n" % ','.join(str(mem[x]) for x in MEMKEYS))
lfp.flush()
else:
sys.stdout.write(".")
sys.stdout.flush()
time.sleep(options.waittime)
except Exception, e:
print "At %d nodes caught exception:\n" % i, e
if retry_count > 0:
print "\nWill retry creating node %d." % i
shutil.rmtree(n.nodedir, ignore_errors = True)
retry_count -= 1
i -= 1
time.sleep(options.waittime)
continue
else:
print "Stopping at %d nodes!" % i
break
if i == options.numnodes:
print "Stopping at %d nodes due to numnodes option." % i
break
# node creation was successful at this point
retry_count = options.retries
if lfp:
lfp.flush()
lfp.close()
print "elapsed time: %s" % (datetime.datetime.now() - start)
print "Use the core-cleanup script to remove nodes and bridges."
if __name__ == "__main__":
main()